Sizing pipe ends



Oct. 19, 1954 R FIN H 2,691,906

SIZING PIPE ENDS Filed Aug. 15 1949 m INVENTOR HARRY J. FINCH Patented Oct. 19, 1954 SIZING PIPE ENDS Harry J. Finch, Oil City, Pa., assignor to Jones & Laughlin Steel Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Application August 15, 1949, Serial No. 110,266

7 Claims.

This invention relates to sizing pipe ends. It has to do particularly with improved apparatus for sizing pipe ends whereby the sizing is accurately and efficiently performed, provision being made for simultaneously sizing both ends of a pipe, the sizing dies being constructed so as to readily release the sized pipe ends.

My invention is applicable to the sizing of pipe of various types adapted for various purposes. For example, it may be employed for the sizing of thin-Walled steel pipe or tubing of the type disclosed in my copending application Serial No. 90,071, filed April 28, 194:9, now Patent No. 2,669,139, issued February 16, 1954. For purposes of explanation and illustration the invention will be described as embodied in apparatus for sizing thin-walled metal tubing, the tubing being cut into sections and each section having one end expanded to form a box end for cooperation with the pin end of a similar section, the box end having internal threads rolled thereinto and the pin end having external threads rolled thereinto. The rolling of the threads into the pipe may for example be accomplished as described in my said copending application. While my sizing apparatus is described as embodied in apparatus for sizing threaded pipe ends it is also adaptable for the sizing of unthreaded pipe ends.

I preferably provide means engaging a pipe intermediate its ends holding it against substantial flexure transversely of its length while permitting it to move axially, the pipe being engaged by such means during sizing. I am thus enabled to exert substantial axial force against the pipe at its ends during the sizing operation without danger of buckling of the pipe at its intermediate portion. Also, since the pipe is free to move axially, it may readily be presented to the sizing dies. While both sizing dies may be mounted on heads which are bodily movable axially of the pipe into and out of cooperative relationship with the pipe upon each sizing operation I find it preferable to mount the sizing die for operation on one end of the pipe in relatively stationary position and move the sizing die for operating on the other end of the pipe toward the pipe to engage the second mentioned end thereof and push the pipe into the stationarily mounted sizing die so that both ends of the pipe are sized through the application of moving force applied at one end.

The means for engaging the pipe at its intermediate portion during the sizing operation may comprise supporting means to which the pipe is adapted to be delivered and holding means operating with the supporting means to hold the pipe against substantial flexure transversely of its length during sizing. The holding means are moved to inoperative position at the completion of the sizing operation on each pipe to permit the sized pipe to be removed and. another pipe delivered to the supporting means. The pipe may be handled mechanically by apparatus of the type disclosed in my said copending application. The holding means may be operated by fluid pressure and may consist of any appropriate number of holding members desirably spaced along the pipe. One of the holding members may serve as means for stripping the pipe from one of the sizing dies. For example, the pin end sizing die may be the movable die and at the conclusion of the sizing operation it may move away from the box end sizing die, removing the sized box end of the pipe from the box end sizing die. The sized box end may engage one of the holding members to restrain the pipe against further axial movement toward the pin end sizing die resulting in stripping of the sized pin end of the pipe from the pin end sizing die. That holding member is preferably actuated by hydraulic pressure as distinguished from air pressure because of the substantial force exerted against it in the stripping operation just referred to, but other of the holding means may, if desired, be actuated by air pressure.

The sizing dies are designed to effect the sizing action rapidly, accurately and efficiently and to readily release the sized pipe ends while being of relatively simple construction. The sizing dies are desirably sectional and collapsible to permit withdrawal of the sized pipe ends while being rigid and unyielding during the sizing operation when the pipe ends are being forced into cooperative relationship with the dies.

Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds.

In the accompanying drawing I have illustrated a present preferred embodiment of the invention, the drawing being .a view partly in plan and partly in horizontal cross section showing dies for sizing the pin and box ends of a length of thin-walled steel tubing having threads rolled thereinto.

Referring now more particularly to the drawings, the pipe being sized is designated generally by reference numeral 2, the head carrying the pin end sizing die is designated generally by reference numeral 3 and the head carrying the box size and is maintained in that position throughout the operation.

The head 3 is movable axially of the pipe for each cycle of operations, 1. e., for the sizing of each individual pipe. The head 3 is desirably carried by the piston rod of a piston operating within a double acting hydraulic cylinder so that an appropriate amount of force may be exerted to advance and retract the head.

Each pipe during the sizing operation is carried by supporting members '1, a desired number or"- such supporting members being positioned alon the intermediate portion of the pipe. The supporting members i might, if desired, be combined into a single elongated supporting member. Each of the supporting members I has a laterally open pipe receiving portion 8 of generally semi-cylindrical shape in which the pip is adapted toseat. The portion 8 is of slightly greater internal diameter than the external diameter of the pipe. Suitably mounted for horizontal sliding movement toward and away from each supportin member I is a holding member l of a shape which is complementary to that of the supporting member so that when the holding member is clamped against the supporting member the pipe is held by the two members cooperatively against substantial flexure transversely of its length although it is free to move axially. In other words, the supporting and holding means maintain the pipe against bending while providing a sliding fit on the pipe so. that the pipe may b moved relatively thereto upon movement of the head 3.

Each holding member I 0 is connected with the piston rod l3 of a piston operating in a cylinder I l Operation of the piston in the cylinder M moves the holding member it between operative position relatively tov the corresponding supportingv member I and inoperative position which leaves the supporting member 1 unobstructed so that a sized pipe may be removed and another pipe introduced to the supporting members. The pistons in the. cylinders [4 may be operated by any suitable fluid although for reasons which will presently appear it is desirable that at least the piston in the cylinder nearest the box end sizing die be operated by hydraulic fiuid.

Control means are provided for operating the pistons in the respective cylinders l4 synchronously so that all of the holding members H] are moved simultaneously from operative to inoperative position and vice versa. When the holding members are in inoperative position as shown in the drawing a pipe is introduced into the portions 3 of the supporting members i whereupon the holding members It are moved to operative position to hold the pipe against substantial transverse flexure while permitting it to move axially and the sizing dies are operated as will presently be described to size the pipe ends. After the pipe ends have been sized the movable head 3 is moved toward the right viewing the drawing carrying with it the sized pipe whose box end is withdrawn from the box end sizing die. Movement toward the right of the head 3 with the pipe 2 carried thereby continues until the shoulder defining the box end of the pipe engages the support I and holding means l0 which are nearest the head 4, such support and holding means serving as a stripper to hold the pipe against further axial movement to the right while the pin end is stripped from the pin end sizing die. The pipe will move initially with the pin end sizing die as the gripping pressure on the pipe exerted by that die is greater than that exerted by the box end sizing die.

Connected with the head 3 by a pin I5 is a plug i6 having a portion I! of maximum diameter, a portion l3 of somewhat smaller diameter, a curved inwardly recessed portion 19 and a cylindrical portion 26] of somewhat less diameter than the portion l8. Projecting axially of the plu |t is a reduced conical end portion 2| from which protrudes a screw 22. Mounted about the conical end portion 2| are sectional internal sizing dies 23. The dies 23 have a circumferential recessv 24 in which is positioned a circular holding spring 25- for holding the dies 23 inv position about the conical portion 2|. Disposed over the screw 22 is a plate 26 which bears against the outer ends of the dies 23. A compression coil spring. 21 bears against the plate 26.. A nut 28. is threaded onto the end of the screw 22, the coil spring 21 pressing against a washer 29 held in placeby the nut 28. The springs 25 and 21. maintain the die sections 23 in place about the portion. 2|. and against the shoulder 3|) between the end of the portion 28 and the conical portion 2|. Thedies 23 are somewhat spaced apart. when in the position in which they are shown in the drawing, a space. 3| between two of. the dies being shown. The spaces between the dies. are disposed at. an angle to the axial direction soas not. to interfere with the sizing action of the dies.

collapse inwardly since they are moving from a.

portion of relatively large diameter to a. portion of relatively small diameter of the conical. portion 2| of the plug 16 and the circular spring 25 addition to the force exerted by the pin end of the pipe tending to collapse th dies. A sleeve 32 surrounds the plug IB- and is fastened thereto by fastening screws 33'. The bore-off the. sleeve 32 has its outer end. rounded as shown at 34' and has a portion 35 of maximum diameter; an inclind portion 36- and. a portion 31. of. smaller. diameter. When the pin end of the pipe enters; between the dies 23 andthe sleeve 32 it is sized by the conjunct action thereof and the extremity of the pin end is constrained to flow inwardly to form an extreme end portion or pilot 38 'of minimum diameter to facilitate entry of the pin. end into the box end of a similar pipe.

Connected with the head'4' by fastening, screws 39 are supporting members 40. Connected. with the supporting members 40 by bolts 4| is a diecarrying member 42 having a conical recess 43 and a shoulder 44 at the inner end of the conical recess. Sectional outside sizing dies 45 are posi.-. tioned in the conical recess 43 as shown, the dies having inner pipe engaging faces 46 and. inclined cut back inner front edges 41. A plate 48 yield ably maintains the dies 45 against-the shoulder 44. Bolts 49 are threaded intothe plate at; 50.

and extend through bores 5| in the member 42, compression coil springs 52 bearing between the bolt heads 53 and the rear face of the member 42. The projecting portions of the bolts 49 lie in between the members 40.

The head 4 has a central conical projection 54 having a shoulder 55. Surrounding the projection 54 are inside sectional dies 56 which operate similarly to the dies 23. The dies 56 are yieldably maintained against the shoulder 55 by a compression coil spring 5'! bearing against a plate 58 which engages the outer faces of the dies. The spring 51 is disposed about a bolt 59 threaded axially into the projection 54, a nut 60 being threaded onto the bolt and pressing a washer 6| against the spring 51. The sectional dies 45 and 56 operate in a manner analogous to the manner of operation of the sectional dies 23 above described.

When a pipe has been positioned in the supporting members I and the holding members 10 are rendered operative to hold the pipe against substantial flexure transversely of its length While permitting it to move axially hydraulic fluid is admitted behind the piston in the cylinder for operating the head 3 and that head moves toward the left viewing the drawing. The inclined front edges 62 of the dies 23 act as a pilot to cause the pin end of the pipe to ride over the dies 23 and the rounded front edge 34 of the sleeve 32 insures entry of the pin end between the dies 23 and the sleeve 32. At the same time the pipe is moved toward the left, the box end being guided by the inclined inner front edges 41 of the dies 45 to enter the passage formed by the dies 45 and then to pass between the dies 56 and the member 42. Sufiicient pressure is exerted endwise against the pipe by movement to the left of the head 3 to insure both ends of the pipe passing completely into the respective sizing dies. The box end dies offer less resistance than the pin end dies so the box end of the pipe is promptly seated in the recesses 53 of the dies 56 while the extreme end 38 enters the space between the portion l8 of the plug l6 and the sleeve 32. Thus both ends of the pipe are simultaneously sized.

As soon as the pipe ends have been sized the head 3 is backed off toward the right viewing the drawing. Since the pin end of the pipe is gripped between the dies 23 and the sleeve 32 more tightly than the box end is gripped the sized box end of the pipe will move out of the box end sizing die. The inner dies 56 are free to move inwardly along the conical projection 54 upon yielding of the spring 51. The outer dies 45 are free to move outwardly along the conical recess 43 upon yielding of the springs 52. When the shoulder defining the box end of the pipe engages the support I and holding member I0 nearest the head 4 movement of the pipe toward the right is arrested and the pipe is stripped from the pin end sizing die. The sectional dies 23 are permitted to move outwardly along the conical projection 2| by yielding of the spring 27 to free them from the sized pipe end. Thus the sized pipe is freed from both the pin end sizing die and the box end sizing die and lies in the supports I ready to be discharged therefrom. The holding members Ii} are moved to inoperative or open position, the sized pipe is removed from the supports 1, a new pipe is placed in the supports, the holding members are again rendered operative and the cycle is repeated.

While I have shown and described a present preferred embodiment of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. Apparatus for sizing pipe ends comprising means engaging a pipe intermediate its ends holding it against substantial flexure transversely of its length, said means being of slightly larger size than the pipe whereby to permit the pipe to move axially, sizing means for sizing one end of the pipe, said sizing means being mounted in stationary position in line with the pipe axis, and other sizing means for sizing the opposite end of the pipe, said second mentioned sizing means being mounted in line with the pipe axis and movable along the pipe axis into engagement with the second mentioned end of the pipe to move the pipe axially until its first mentioned end engages the first mentioned sizing means and then press the pipe axially between the two sizing means to substantially simultaneously size both ends thereof.

2. Apparatus for sizing a pipe end comprising a sectional die and a support disposed generally within the sectional die relatively to which the die sections are movable generally at an acute angle to the axis of the pipe, the support having means connected with the die sections holding the die sections against inward retraction from the pipe end when the pipe end is being advanced over the die to size it but when the pipe end is withdrawn after sizing permitting ready retraction of the die sections inwardly to facilitate withdrawal of the pipe end.

3. Apparatus for sizing a pipe end comprising a sectional die and a support disposed generally about the sectional die relatively to which the die sections are movable generally at an acute angle to the axis of the pipe, the support having means connected with the die sections holding the die sections against outward retraction from the pipe end when the pipe end is being advanced into the die to size it but when the pipe end is withdrawn after sizing permitting ready retraction of the die sections outwardly to facilitate withdrawal of the pipe end.

4. Apparatus for sizing a pipe end comprising a sectional die, a support disposed generally within the sectional die relatively to which the die sections are movable generally at an acute angle to the axis of the pipe and a die portion disposed beyond the sectional die in the direction of advance of the pipe end over the die during sizing to slightly decrease the diameter of the extreme end portion of the pipe end, the support having means connected with the die sections holding the die sections against inward retraction from the pipe end when the pipe end is being advanced over the die to size it but when the pipe end is withdrawn after sizing permitting ready retraction of the die sections inwardly to facilitate withdrawal of the pipe end.

5. Apparatus for sizing a pipe end comprising a die having sectional portions arranged in tandem, said portions respectively acting on opposite sides of the pipe wall, the apparatus having means maintaining the sections of each of the sectional die portions mounted for rigid cooperation with the pipe end as the pipe end is advanced relatively thereto during sizing thereof but permitting retraction of the sections away from the pipe wall upon withdrawal of the sized pipe end.

6. Apparatus for sizing pipe ends comprising sizing means respectively engageable with the aeensoa:

pim arr'd-i. box: endscofi a. pin. and box: end pipe: and

relatively movable: toward: each other." to substantially' simultaneously size: both endsof. the pipe and relatively movable away from each; other to disengage the. sized pipe; means positioned to engage the pipe intermediate. the ends thereof while the ends are being sized to guide the pipe for axial movement while holding it against transverse movement, the apparatus having means stationarily mounted in position in the path of movement of the sized box end of the pipe after it has been disengaged from thesizing means; cooperating therewith to restrain the pipe against axial movement toward its pin end and topermit disengagementof. the sizing means cooperating with the pin end of. the pipe from the pin end. of the pipe by moving such sizing meansv axially of the pipe and relatively to the pipe in said direction.

7. Apparatus for sizing the ends of pin and box end pipe comprising means engaging apin and box end pipe intermediate its ends holding it against substantial flexure transversely of its length, said means being of slightlylarger size than the pipe whereby to permit the pipe to move axially, box end sizing means'for sizing the box end of the pipe, the box end sizing means being mounted instationary position in line with therpipe axis, and pinend sizing means for sizing the pinend of thepipe, the pin end sizing means being mounted in line with the pipe axis and movable along. the pipe axis into engagement with the pin end of the pipe to move the pipe axially until its box end engages the box end sizing-means and. then press the pipe axially between the two sizing. means to; substantially simultaneously size. both. ends thereof, meansiyieldinglyopposing; release of the respective. ends of. the pipe from; the respective sizing means, such means opposing: release of the pin end ofc'the pipe; from thepin, endsizing means being stronger than such means opposing release of the box end of the pipefrom: the box end sizing means so that as the pin. endr'. sizing means are moved away from the-box end: sizing. means after the pipe ends; have been SiZEdli the pipe moves with the pin end sizing means: and is disengaged from. the boxtendisizing means;. the holding means havinga portion stationarilytmounted in position in the path of movement: ofi the sized boxv end of the pipe after it. has'been disengaged from. the box endjsizingmeans torre strain the pipe against axial movement in the? direction toward its pin end topermitdisengagee ment of the pin end sizing meansi'from the: pin: end of the pipe.

References Cited in the file. of" this patent.

UNITED STATES PATENTS Number Name Date 1,144,839 Guenther June 29, 1915 1,365,073 Allerton Jan. 11 1921' 1,475,032. Shrum et a1 Nov. 20', 1923 1,651,231 Shrum Nov. 29; 1927 1,671,697 Burke May 29, 1928" 1,677,860 Ferris July 17 1928 2,023,657 Wilson Dec. 10-, 1935- 2,219,279 Gaspar 1- O'ct..29 1940. 2,249,984 Seever July 22, 1941- 

